The invention relates to control equipment for guiding a drill rod, the control equipment comprising a frame, two guide jaws provided with guide surfaces and mounted to be linearly movable in relation to the frame, between which guide jaws the drill rod is to be set during drilling, and actuators for moving the guide jaws transversely to the drill rod axis for moving them away from one another, and correspondingly, towards one another in order for guiding the drill rod.
Drilling rigs often employ drill rods of different diameters, typically two different drill rods. During drilling the drill rods must be guided and for that there are typically employed two separate controllers, i.e. one for each rod diameter. Each guide requires a separate hydraulic system for operating the controller, and consequently the operator must also have separate control means for each guide, respectively. Further, the use of double devices increases the weight of the equipment, and in particular in a location disadvantageous to the equipment, i.e. at the end of a feed device.
From U.S. Pat. No. 7,814,994 is known a solution which employs one device for supporting rods of different diameters. This solution comprises generally V-shaped guide jaws on either side of the drill rod and they are both fed with a specific hydraulic cylinder towards the drill rod until they come into contact with the drill rods. This device works unreliably to some extent, because the guide jaws may move differently, and there is no certainty whatsoever about the actual position of the guide jaws. In addition, in the solution of the publication the guide jaws in the guide position are in continuous contact with the drill rod, which causes unnecessary friction and wear.